In recent years the use of supraglottic airways has become widespread. Most of the devices include an airway tube having an inflatable cuff mounted at the distal end. The cuff includes a recess which is in fluid communication with the airway tube to allow anaesthetic gas to be administered to the lungs of a patient, or alternatively in an emergency situation to allow air to pass in an unobstructed way to the lungs of a patient.
It is desirable that the artificial airway should form a good seal around the glottic opening of the patient. This has the advantage that substantially all of the anaesthetic gas supplied through the airway passes to the lungs of the patient. Further, the seal helps to prevent any regurgitated material entering the lungs of the patient.
In some known devices an evacuation tube is provided so as to communicate with the oesophagus of the patient so that any regurgitated material can be vented through the evacuation tube, thereby minimising the possibility that the regurgitated material enters the lungs of the patient. Normally suction is applied to the evacuation tube to facilitate this process as disclosed in AU-B-52036/90 for example.